Delayed Payment Module

[TimBWolf]

Is there a method to delay a payment based on other criteria in an order being processed?
Example:
I am selling a Whole New york Strip which average 12- 15lbs. I sell this on a per pound price so the exact weight will vary slightly by as much as 1 - 3 lbs. So I'm wondering can I accept the order online, prepare the order ( package it on site), then take the prepared order price and process the sale? i'm thinking the only option i have is to set up an instore payment module. But perhaps there is a way to update an order placed with accurate pricing and ask the customer to return online and pay? I hope this isn't to confusing and someone can provide some guidance.
thank you

[kobra]

You might look at the 3rd party purchase order module and change the text presented

[Phosphoric]

I am looking for the same thing, I have some items that I would like to be available... but price is based on weight.